When Richard Garrin rehearsed with Masterworks Chorale for the first time, he found the singers "highly skilled and very receptive to changing their singing to whatever I mentioned, and they could do it the first time," he said.

That was last spring, when Garrin was one of eight finalists to succeed Masterworks founder-director Galen Marshall, who was retiring after 33 years with the chorus, which is based at College of San Mateo. Each finalist was invited to spend part of a Monday night rehearsal with the 140-voice volunteer community chorus.

The responsiveness that Garrin found that night with Masterworks "happens in the professional world" but not usually in the nonprofessional world, he said, noting that he was referring to qualities like vocal color and articulation of phrases.

Evidently the admiration that Garrin felt for the chorus was mutual because he is its new director. He made his concert debut with Masterworks Chorale and its orchestra last weekend in a program featuring a cantata by Benjamin Britten, "St. Nicholas," Op. 42, and other works.

Garrin comes to the Peninsula from his hometown of Chicago, where he spent 18 years with the Chicago Symphony Chorus. His tenure there included 12 years as associate director with the renowned Margaret Hillis, the chorus's founder and director emeritus.

During the 1994-95 season he was a guest conductor for the Seattle Symphony Chorus and worked with the Seattle Men's Chorus. Upon his return to Chicago in 1995, he founded Richard Garrin's Voices of Chicago, a professional choral ensemble.

He decided to leave Chicago because he was looking for a job with a large chorus and affiliated orchestra and because he wanted to teach on the college level, he said.

The Masterworks job fills both requirements because the director also teaches at CSM. Garrin teaches voice classes now and will teach a music survey class next semester. He also has founded CSM Singers, a group of 18 students and staff members that he hopes will become a large campus ensemble - part of his dream of building a more extensive vocal music program at the college.

Garrin has some dreams for Masterworks, too. First, he wants to do more recording. The chorus has already released one CD under Marshall, and Garrin hopes there will be others. "Recording is the thing that puts a group on the musical map," he said.

Along with the masterworks that give the chorus its name, he hopes to present works that are "perhaps unusual or not in the standard repertoire" such as "St. Nicholas," which Masterworks had never sung before. He also wants to perform works by living composers who could be here for the concerts and offer master classes or workshops.

He has already taken the first steps toward another goal, a mentoring program for high school students. It will begin with Masterworks' holiday concert, which Garrin has dubbed its first Festival of Singing. Replacing the chorus's annual Messiah sing-along, this program will feature not only the adult chorus but also the CSM Singers as well as choruses from area high schools.

On the program are selections by each chorus, a combined performance of Conrad Susa's "Christmas Garland" and an audience sing-along of holiday music, followed by an onstage party.

Prior to the concert, Garrin and some of his Masterworks singers will go to each school, where he will conduct a rehearsal and the adults will sing with the students. The combined groups also will have two rehearsals before the concert.

"I hope it will be thrilling," Garrin said, adding that he hopes to expand the program over time.

The motivation for this mentoring program is that "it's important that a group like Masterworks do something for the community. I always want to nurture young singers," he said.

The program will give high school students a chance to sing "with very skilled adults and an orchestra." Garrin also hopes that some of those students will attend CSM and help to build its vocal music program.

The need to inspire young singers also motivated him to conduct auditions for Masterworks soloists during his voice classes rather than at some other time. He said his students were impressed to hear classically trained voices at such close range.

Garrin acknowledges that there's always some trepidation when someone from outside the organization succeeds someone who was as well-liked and respected as Marshall. However, "it's been easier because the people are very caring, helpful and nice," he said.

Furthermore, Marshall announced his plans well in advance, and the chorus had a hand in choosing his successor through the auditions as well as through representation on the committee that screened applicants.

To strengthen their rapport, Garrin and the chorus recently had a retreat at a camp in La Honda. There they had rehearsals and workshops to focus on such areas as tone production, diction and rhythm. "It was quite miraculous. People would produce sounds they didn't know they could," he said. They also had a good time just socializing with one another.

The Festival of Singing is slated for 7:30 p.m. Dec. 6. The 1997-98 concert season also includes Mozart's Requiem and Vivaldi's "Gloria" Feb. 28 and March 1; and Daniel Pinkham's "Wedding Cantata," Verdi's "Stabat Mater" from his Four Sacred Pieces, and Kodaly's "Te Deum" May 30 and 31.